I compete in triathlons and need to make up ground in the biking segment.

If you're looking for quick improvement on your bike leg, you have to cheat—cheat the wind, that is. "The body is the biggest drag creator on the bike," says Joe Friel, president of Performance Associates and coach of Wes Hopson and Ryan Bolton, two top 10 triathletes. Buy a pair of aero bars—typically U-shaped clip-on extensions that position your hands close together and your body into an aerodynamic tuck—and learn how to hold that tuck (back flattened, hands in front of your face, elbows tucked in) throughout a long ride. (But do so on a lightly trafficked road, because aero bars make the bike more difficult to steer.) You can add more free speed by making sure the bearings and drive train of your bike are properly lubricated, and that your tires are pumped up to their maximum rating to lower rolling resistance. One technique mistake many novices make is pushing too high a gear, "People start by trying to turn a big gear very slowly." It's more efficient to turn the pedals at a higher cadence—at least 90 rpm. Most accomplished riders spin between 90 and 100 rpm. To improve your fitness in a hurry, Friel suggests hitting the gym. "An athlete who's new to the sport and wants to improve fast should try weight training." He suggests focusing on exercises that work the hip, knee, and ankle joints in concert and improve your ability to impart force to the pedal, like squats, leg press, step-ups, and lunges. (Also, says pro sports trainer Kirk Brumels, "to aid in eliminating any strength differential between the legs, try these single leg exercises: knee extensions, leg curls, and calf raises.) Within a couple of weeks you should be able to push a bigger gear, predicts Friel. To improve your endurance, he advocates going long. "It's not so much a matter of your weekly volume but making sure there's a long ride every week," Friel says. "If you're training for a 40K race, you should be riding a hour and a half to two hours once a week." But don't push too hard. These endurance rides should remain aerobic—you should be able to hold a conversation while you're riding.